Sulphur vacancy defects engineered metal sulfides for amended photo(electro)catalytic water splitting: A review

Vacancy engineering in metal sulfides has garnered enormous attention from researchers because of their outstanding ability to modulate the optical and physiochemical properties of photocatalysts. Typically, in the case of sulfides, the catalytic activity is drastically hindered by the quick reassembly of excitons and the photocorrosion effect. Hence designing and generating S-vacancies in metal sulfides has emerged as a potential strategy for attaining adequate water splitting to generate H 2 and O 2 because of the simulta-neous improvement in the optoelectronic features. However, developing efficient catalysts that manifest optimal photo(electro)catalytic performance for large-scale applicability remains challenging. Therefore, it is of utmost interest to explore the insightful features of creating S-vacancy and study their impact on catalytic performance. This review article aims to comprehensively highlight the roles of S-vacancy in sulfides for amended overall water-splitting activity. The photocatalytic features of S-vacancies modulated metal sulfides are deliberated, followed by various advanced synthetic and characterization techniques for effectual generation and identification of vacancy defects. The specific aspects of S-vacancies in refin-ing the optical absorption range charge carrier dynamics, and photoinduced surface chemical reactions are critically examined for overall water splitting applications. Finally, the vouchsafing outlooks and op-portunities confronting the defect-engineered (S-vacancy) metal sulfides-based photocatalysts have been summarized.(c) 2023 Published by Elsevier Ltd on behalf of The editorial office of Journal of Materials Science & Technology.

Automated summary

Vacancy engineering in metal sulfides has attracted significant attention due to its ability to modulate the optical and physiochemical properties of photocatalysts. This review article comprehensively highlights the role of S-vacancies in improving water-splitting activity and discusses various synthesis and characterization techniques for identifying vacancy defects.